Shrek 4 - Shrek Forever After

I thoroughly enjoyed the first Shrek, even though (at that time) I was a bit skeptical about the new-fangled way of doing what appeared to be little more than beefed up cartoons. I saw Shrek 2 and Shrek 3 with assorted children, and thought they were all right but weren't as good as the original. I even spotted a continuity error in one of them - but shh, best not speak of such things here.
So when I went with Boy 1 and Boy 3 (who have twenty actual years between them compressed into about one year when it comes to film preferences), I wasn't particulary expecting to think that Shrek 4 would be any better than numbers 2 and 3. But I was wrong.
This Shrek unashamedly assumes you know something about the characters from the previous films - without such knowledge, many of the situations and character twists would fall flat as a pancake. The plot is a version of many another story, featuring a small change in the past which produces huge (and unwanted) changes in the future - but forunately our hero (Shrek) gets one chance to put everything right. Which, of course, he eventually does.
I thought the script was right on, the 3D animation was excellent. and the plot just sufficiently different to keep adults happy. I recommend it. One word of warning though: number 3 son told me that he preferred Toy Story 3. I haven't seen that, so I am unable to comment...